Sound-absorbing air vents are used in many places where strong sounds are to be absorbed, even if only part time, in the vicinity of buildings where strong sounds are present and have to be excluded from the inside of the building. Windows and doors have already been developed which are highly efficient with regard to sound absorption without interferring with the entering light to any great extent. However, since a constant air exchange must be present between the inside of the building and its surrounding space, it is necessary to open doors or windows at least part of the time. During that time, the high sound-absorbing effects are lost, or else the windows have to be designed in such a way that they may only be opened during cleaning procedures. In this case, the air exchange is brought about by special venting devices where, sound-absorbing linings have been provided in their air penetration openings or ducts. This is shown in German Pat. No. 23 31 841 and German petty Pat. No. 75 04 175.
Sound-absorbing windows, when closed, may absorb most of the sound peaks, as well as short-time ones. The same effect, however, may not be achieved in the open position of the sound-absorbing venting devices, because, in spite of the linings that have been installed, sound waves may still penetrate through the unempeded cross-section of the ducts through which the air penetrates.
These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide sound absorbing devices may be designed in such a way that they may be inserted into building walls as an individual unit.
Another object of this invention is the provision of sound absorbing devices formed as an integral part of windows and doors, so that they may be mounted together in the corresponding openings of the building walls.
A further object of the present invention is the provision of air vent capable of resisting effectively the penetration of sound waves into the inside space through the venting devices during sound peaks.
It is another object of the instant invention to provide sound absorbing venting device which prevent the penetration of sound waves into rooms originating from sound peaks.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in combination of parts set forth in the specification and covered by the claims appended hereto.